Blowpipe



Jan. 26 1926. 1,571,004

J. HARRIS BLOWPIPE Filed Jan. 19, 1921 2l sheets-sheet 1 Jan. 26, 192e. 1,571,004

J. HARRIS BLOWPIPE Filed Jan` 19. 1921 2 'Sheets-Shea?l 2 Patented Jan. 26, 1926.

JOHN HARRIS, or LAKEWOOD, omo. i

BLOWPIPE. v

Application led January 19, 1921. Serial No. 438,287.

Y 0 all whom t may concern Be it known that I, JOHN HARRIS, a citizen of the United States, residing at Lakewood, in the county ofl Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Blowpipes, of which .the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to blo'wpipes` or torches, such as are employed in the art of welding and cutting metals by gases. It is the general object of the invention to provide a construction which will not only enable the pipe to be employed with gases under llow pressures without detrimental back-firing; but also to provide a construction wherein, should the flame b e propagated to the interior of the pipe, the flame will be immediately blown out, thereby preventing injury to the pipe through the maintenance of aI flame therewithin aswell as preventing injury to the connections leading to the pipe proper through the `propagation of aflame within such connections.

In the welding lof metal by blowpipes operatijng with high pressuregases, the liquid metalis liable to be blown out of the joint by the high velocity of the flame and gases at the end of the reducing flame. By the use of my invention I am enabled' to use gases under low pressure in welding blowpipes, enabling me to produce a smooth weld and without blowing the liquid metal from the joint.

I secure the foregoing objects in and through the constructions illustrated in the drawings forming part hereof wherein Fig. 1, represents a central longitudinal sectional view through the head and tip of a welding pipe constructed'in accordance with my invention; Fig. 2 a sectional detail corresponding to the line 2-2 of Fig. 1; Fig. 3 an elevation of the tip member of the blowpipe; Fig. 4 a detail in elevation of mixing device employed in such tip; Fig. 5 a view, similar to Fig. 1,l of a cutting torch embodying my invention; Fig. 6 a 'sectional detail 'corresponding to the line 6-6 of Fig. 5; Fig. 7

anelevation of the inner member of the tip of such cutting torch; Fig. 8 an elevation of the mixing device; and Fig. 9 a sectional de.

tail corresponding to the line 9-'9 of Fig. 5'.

Describin `the parts by reference characters and wit special reference to Figs. 1 to 4 inclusive, 1 denotes generally the blowpipehead, said head being conveniently formed of a casting terminating in a downwardly 'extending cylindrical portion 2 having its lower end provided with an external thread 3, the cylindrical portion 2 being carried by a lateral extension 4 having a passageway 5 for oxygen and a passageway for acetylene or other combustible gas, the passageway 5 communicating with an oxygen supply pipe 7, the passageway 6 with a combustible gas supply pipe 8, the said pipes being indicated as covered by a handle casing 9 which may be secured to the lateral portion 4 of the head as by a. gland nut 10.

The head 1 is provided with a vertical bore extending upwardly from the lower end thereof. The lower portion 11 of said bore extends rupwardly from the bottom of the lhead proper to an enlargement `12.- From the upper portion of such enlargement, the boreis reduced and upwardly tapered and provided with a thread, as shown at 13,the last mentioned portion of the bore merging with a chamber 14 adjacent to the top of the head and with which chamber the passageway 5 communicates. f

A tip 15 is threaded into the portion 13 of the bore, being provided with a tapered externally threaded portion 16 for. this purpose. From the bottom of the threaded'portion 16, the tip is cylindrical and of a diameter to fit more or less closely the lower portion 11 of the head bore, the enlarged portion 12 of the bore providing an annular vchamber about'the tip with which the passageway 6 communicates. The tip is preferab y `made from a piece of copper tubing having a central bore 17 o 'r'l about 1/8 inch in diameter,

said bore being enlarged near theupper end of the tip, as indicated at 18, the upper end of such enlargement being internally threaded, as shown at 19, and a ledge or shoulder 17 a being provided between the portions 17 and 18 of the bore. The lower end of the tube is swaged'inwardly, as shown at- 20. In practice, the swaging of the lower end of the tube will not only gradually reduce the bore, as indicated at 17", but will vcompletely close the lower end of the same.

After such closing, the lower end of the tip is drilled. as indicated at 21, to provide a discharge orifice of the proper size, that made kby a No. 51 drill having proven eicient.

In the enlarged portions 18 and 19 of the bore there is mounted a' mixing device 22, said mixing device having an external v on the. shoulder 17?.

chamber I being preferably inclined downwardthread 23 by means of which it is detachably fitted into the upper portion 19 of thebore, the outer portion 22 of said mixing device, below the thread 23," preferably forming a close fit with the bore section 18, the lower end of the mixing device being seated provided with a central bore 24 which is preferably of the same diameter as the outlet 21, the upper end of the mixing device being provided with a head 25 adapted to seat on top ofthe tip and provided with a slot 26 for the reception of a screw driver or other suitable tool.

i At a short distance above its bottom, the mixing device 22 is provided with an annular recess 27, said recess providing with theadjaccnt wall of the bore 18 a distributing chamber through A. which combustible gas supplied to the chamber 12 may be conducted through ports 28 in the tip 15 and ports 2 9 in the mixing device to the bore 24. The

cross-sectional area of the ports 29 is much smaller than that of the passageway 21 and bore 24; I have shown five passa eways 29 and each will be preferably less t an 1,/5 of the cross-sectional area of the passageway 24.

The tip 15 is centered with respect to the head by means of a gland nut 30 threaded upon the lower end of the head and having a flange 31 at the bottom the tip, the s the bottom'o adapted to engage ace enclosed by said flange, the head, andthe enclosed wall of the tip being provided with a pack-` ing 32 which will prevent the leakage of any gas from the chamber 12.

. With the parts constructed and arranged; as described, oxygenadmitted through the pipe 7 and the passageway 5 will enter the central bore or passageway 24 of the mixing device. The combustible gas will also be admitted to said bore or passageway through the pass .way 6, chamber 12, ports 28.,

geand ports 29, the last mentioned ports ly toward the lower end of the bore 24. A

feo

detonatingtmixture of oxygen with the combustlble gas will be `formed between the delivery -ends of the ports 29 -and the bottom :of the bore 24 and l "the expansion chamber 1 7 provided .betweenwill be discharged into the bottom of the burner orifice 21. v

Because ofthe construction and arrangement of the parts it has been found Apossible to operate the torch or blowpipe under a very low pressure of gases, with substanmixlng device and the ltially no liability of the flame being propagated into the chamber 17 This is believed to be dueto the fact that, vbecause of the manner of supplying the gases tothe expansion-chamber 17 in the stantially even preure'throu'ghout the exthe production of a' vacuum therein.

-tent of said. hamber with no tendency to The mixing device is providing means tip, there is a'subthermore, should the flame be propagated into the expansion chamber, times occur, the mixture therein vwill immediately explode and the liame will be immediately extinguished by being blown out of said chamber by such explosion through the orifice 21, due to the fact that this orifice provides a path of least resistance for the explosive wave produced by this action. It is therefore impossible .for a flame to be maintained within the chamber 17, so that it is equally impossible for any injury to be doneto the interior f the tip through such iame. Furthermore, because of the restricted area of the ports 29, no iame can be propagated through these ports into the chamber 12, or in fact into any art ofthe conduit for supplying combustl le gas to the tip.

-In Figs. 5 to 9 inclusive there is shown the manner in which my invention may be employed in connection with a cutting torch. This torch' is shown as provided with a head 33- provided with a chamber 33a in the upper portion thereof, said chamber communicating withavertical passageway 34 which merges with an internally threaded bore 35, the lower end` of said bore in turn merging with a cylindrical chamber 36 which extends to the bottom of the head.

A tip comprising an innermember 37 and an outer member 38, preferably pinned 4together, is connected to the head, the inner member being provided with a central bore 39 adapted to register with'and form a continuation of the passageway 34, the lower or delivery end of said bore being contracted by swaging the tubing of' whichthe inner member is composed, after which. the tubingV is drilled to provide a centrally restricted jet'oriice 39, The upper end of the inner tip member is provided with a thread, whereby it may be detachably connected to the head through the threads 35.

Below the threaded portion 35, the. inner tip member is slightly reduced in crosssection and, beneath this reduced portion, is provided with .an upper cylindrical enlargement 40. Below the lower end of such enlargement, the said member is provided with a short cylindrical enlargement 41 merging at its lower end with arusto-conical sur- A face 42. The portions 40, 41 and 42 are adapted to lit snugly-within the ,outer tip member, the projections or enlargements for centering the inner member within the 'outer member as well as means whereby passageways may be provided for the mixture of preheating gases conductedto the delivery end of the pipe.

Opposite sides of the enlargement 40 are cut away, as shown at 40 whereby passageways will be provided on opposite sides of such enlargement and between the same and the outer tip member.

aS may Somewill' be centered with respect to the lowerl end of the head and a gas-tight joint providedbetween the outer tip member and the head by"means of a gland nut 43 which is threaded onto theiower end of the head and provided with a lian'ge'` 44 adapted to fit the outer surface 'of the outer tip member, there being packing 45 interposed between said fiange and the lower end ott the head.

. The blowpipehead is provided with a lateral extension 33"' having a branched passageway 46 communicating with the cham` ber 33a, a passageway 47 extending to an annular chamber provided by a downwardly inclined bore 48 extending from the top of the lateral branch of the head between the branches of the passageway 46. The lower end of the bore 48 isreduced, as shown at 48, the reduced portion of the bore communicating with the upper end of the chamber 36 and a shoulder 48b being provided between the portions 48 and 48a of said bore. A third passageway .49 Acommunicates with the enlarged portion 48 .of the bore just above the sl'ioulder'48". Pipes 50, 5l

and 52 respectively conduct oxygen for cutting purposes to the passageway 46,' oxygen for preheatin purposes to the passageway 47, and acety ene or other combustible gas for preheating purposes to Athe passagef way 49.

Within the bore 48, 48a, is a mixing d'evice, said mixing device comprising 'a stem 53 of smaller diameter thanthe bore 48 and having a threaded enlargement 53n whereby the injector may be applied to and re moved from the bore 48 which is internally threaded for this purpose. Beneath the en; largement 5 3, the mixing device stem is reduced, as'shown at 53?, and 'is further reduced, as shown at 53C, the lower reduced portion forming a close lit with the bore 48. The mixing device is provided with a central bore 54 extending upwardly from the lower end thereof as far asa series of` radial ports -55 which communicate with the chamber provided above the threadedV extension orv enlargement 5 3, Similar radial ports 56 fareprovided in .the portion 53h, whereby the-central bore of (the mixing device is placed in communication with the chambersurrounding such portion 53b and with which the passagewa u 49 communicates. In order to form a eak-prootjoint between the head 534 of the' mixing device 'aand the head of the 'blowpipe, a packing washer 57 is ap lied to said stembetween the head thereo and a seat on the head of the blowpipe.

The area of the central bore of the mixing ln the operation of a cutting torch y constructed in the manner described. oxygen for cutting purposes is admitted to the bore 39 of the inner tip member through pipe 50, passageway 46 and chamber 33. (lxygen for preheating purposes is admitted through the -pipe 51, passageway 47 and the radial ports 55 to the central bore of the mixing device and, passing along said bore, meets lthe combustible gas supplied through the ports 56 from passageway 49 and pipe 52, and the explosive or detonating mixture produced within the mixing de-V vice is discharged into the expansion chamber 36, whence it is delivered to the preheating outlets 42".

As inthe case with thev welding pipe or torch, should the ame be propagated into y tip, the said oriices offering a pathof least resistance for the exploslveA wave. The

lutely prevents aniy flame from being propagated therethrough and into the chambers surrounding the mixing device and the passageways and connections communicating with said chambers. Furthermore, owing to the shape of'the expansionk chamber and the arrangement of the mixing device with respectthereto, there will'be no tendency tog a vacuum or a partial vacuum within the expansion chamber; hence the liability of propagation of llame into such chamber isv reduced to a minimum. r I,

The general construction' of the inner tip member of the cutting blow ipe, including the passageways for pre eating gases formed between said member and the outer member, is shown here as'substantially identical with the construction of the corresponding parts in my application No. 225,- 431 file-d March 29, 1918, wherein the details of such construction are claimed.

lsmallness of the radial ports 55 and 56 abso- A Having thus described my invention, what additional to said tip member and arranged' to discharge its contents into'said chamber, means for sup lying oxygen to the bore of said mixing evice, there being restricted ports extending through the wall ofthe mixing device from said bore, and means :for.supplying a' combustible gas through said-head and through said ports into the bore of said mixing device, the cross-sectional area of the outlet or outlets being at least as great as the cross-sectional area of the mixing device bore and atleast as great as the aggregate cross-sectional areas of the ports for combustible gas communicating with said bore. i

2. In a blow ipe, the combination of a,

head, a tip meni r secured to said head and provided with an expansion chamber havin one or more-burner outlets therebelow aiild communicatin therewith, and a mixing device additiona to saidgtip member and having a bore arranged to l discharge into the upper end of said' chamber, there being an annular chamber in said head surrounding the said mixing device above the lower end Athereof and a plurality of restricted ports extending through the wall of said mixing device and placin the annular chamber in communication with the bore thereof, said head having a assageway for combustible as communicating with said annular chamr and a second passageway for oxygen arranged to discharge into the bore of the Iixing device above the said aiinular cham- 3. In a blow ipe, the combination of a head, a tip mem r secured to said head and provlded with an expansion'chamber having a burner outlet therebelow and comsaid head for supp chamber, discharge municating therewith, a mixing device additional to said tip member, and means in ying oxygen and a combustible gas to said device to produce anexplosive mixture therein, the delivery` end of .said device bein arranged to discharge such mixture into outlet being so oportioned that a path of least resistance ig provided for an explosive wave from said chamber.

through said outlet. l

t e upper portion o'f said the mixmg device bore and thev 4. In a blowpipe, the combination of a tip comprising an inner' and an outer member, the'inner member being provided with a discharge outlet and an tending thereabove, there being a plurality ofv restricted ,discharge outlets surrounding the lirst mentioned outletand communicating at theiruper e`nds with an expansion chamber provi ed between the inner and the outer tip members, a blowpipe head having a central bore providing an upper extension of said expansion chamber, means detachably connecting said tip to said bore, said head. having a passageway for supplying cutting oxygen to the bore of the inner tip member and an inclined bore communicatinflr with the upper end of the expansion chamber, and a-mixin ldevice mounted in said inclined borefsai mixing device having longitudinally spaced series of restricted ports extending outwardly from the bore thereof and each series communicating with a chamber rovided between the mixing de-`v vice and the bore wherein it is mounted, said head-having a passageway for oxygen communicating with one of the two last mentioned chambers yand a passageway for combustible gas communicating with the other of said last mentioned chambers.

5. In a cutting torch, the combination of a head having an expansion chamber, a tip having -a plurality of dischar e outlets for preheating ases communicating with said expansion c amber and 'a central orifice for cutting oxygen, means for sulpp ying cutting oxygen to such central ori ce, devicea apted to discharge into the upper end of the expansion vchamber and having two longitudinally spaced series of restricted ports extending outwardly from the bore and through the wall thereof, means for siip- 4 plying oxygen to one of such series of ort-s, and means for supplying a combustib e gas to the other series of ports, the aggregate area of the tip outlets for preheating gases being at 'least as great as the cross-sectional. area of the bore of the mixing device.

In testimony whereof, I hereunto alix my signature.

enlarged bore ex- -a Vmixing 

